Pneumatic tool.



C. O. PALMERJ PNEUMATIC TOOL.

APPLICATION FILED NOV. 6. 1911.

1,154,797. Patented Sept. 28, 1915.

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COLUMBIA PLANOGRAPH co., WA SHINGTON. 1). c.

C. 0. PALMER.

PNEUMATIC TOOL.

APPLICATION FILED NOV-6.1911.

1, 154,797. Patented Sept. 28, 1915.

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CHARLES OTIS PALMER, 0F CLEVELAND, OHIO.

PNEUMATIC TOOL.

'Speeificeition of Letters Patent.

Patented Sept. 28, 1915.

' ,ApplicatioafiledNovember6, 19.11. .Seria1,No. 658,659.

To all whom it may concern: I

Be it known that 1, CHARLES Oais PALMER, a citizen of the United States of America, residing at Cleveland, in the county .of (luyahoga and State of Ohio, have invented certain new and useful Improvements in Pneumatic Tools, and I :hereby declare the following to be a full, clear, and .eXact description of the invention, such as will enable othersskilled in the art to which it :per tains to make and use .the same.

My invention relate to improvements in Pneumatic Tools and are intended for use in connection with pneumatic picks, rock drills, channeling machines, .etc., that have a reciprocating piston in a toolcylinder for operating on the material. It is intended especially for use in connection with that class of pneumatic apparatus in which the .tool piston is reciprocated by oscillating currents of air as will be noted hereafter.

I will now briefly refer to my inventions as applied to a pneumatic coal pick and from which the application of the same .to rock drills and other pneumatic tools will be readily understood.

In the accompanying drawings-Figure 1 is a side view on a small scale of :a pneumatic pick provided with my inventions and mounted on trunnions and supported on a portable track as shown in my Patent No. 800,41'79 for a mining machine dated Sept. 26, 1905; Fig. 2 is a side view .of a rock drill provided with my inventions and mounted on a guide shell in a'well known manner; Fig. 3 is a view of my hand valve H in detail showing the side toward the air gates G1 and G2; Fig. 4 is a longitudinal section in detail of my hand valve H viewed at right angles to Fig. 3; Fig.5 is a view of my hand valve showing the side opposite the gates G1 and G2; Fig. '6 is a section on line 66 of Fig. 3; Fig. 7 'isa section on line 77 of Fig. 5; Fig. 8 is a detail side view of the bypass valves 42-1 and '02; Fig. 9 is a horizontal section of the power pick on line 9-9 of Fig. 13, showing the handle H in posit'ion to start the piston forward or to holdit in the front end of the cylinder as shown in Figs. 11 and 13; 10 is a horizontal section on line 101O of Fig. 12 .and shows the hand valve H in position to start the piston backward or t h ld it in the back end of'the cylinder; Fig. 11 is a section on line 1111 of Fig. 9 showing valve H in the position shown in Figs. 9 and '13; Fig. 12 is a section on line 12-12 of Fig. 10 showing valve H as in that figure; Fig. 13 is a section on line 1313 of Fig. 9 showing the hand valve H in same position as in that figure; Fig. 14 is a section on line 1313 of Fig. 9 but with hand valve H in the middle position for ordinary work which allows the air free passage in both directions; Fig. 15 is a section on line 1515 of Fig. 9 with the valve in same position as in Figs. .9 and 11; Fig. 16 is a section on line 1616 of Fig. '10 with the hand valve in position for air to enter cylinder as in said figure; Fig. 17 is a section on line 15-45 of Fig. 9, but with valve H set in notch 17a of Fig. 11 where all air is shut off; Fig. 18 is a section on line 1515 of the main back port with valve H set at notch 18a of Fig. 11.

The same characters designate the same parts throughout the several views.

The arrows on thepiston indicate the di rection it is moving and in the air passages the direction the air is moving as stated in the description.

The pneumatic coal'pick has a cylinder T which when in use is situated within striking distance of the working face of the coal.

The air pressor or oscillator not shown is of the reciprocating type, and is located near the tool to which it is connected by two tubular connections F 1 and F2 which join the ends of the tool cylinder with the oscillator forming a closed air system. The air in the tubular connections F1 and F2 oscillates back and forth toward and from the tool. The direction of flow in one tube generally being simultaneously the reverse of the other. The oscillator or air pressor which is preferably of thetype shown in either my application for compressed air apparatus, Ser. No. 369,258 filed April '20, 190.7, or Ser. No. 393,'386 filed Sept. 17, 1907, or Ser. No. 514,029 filed Aug. 21, 1909, may be-driven by an electric motor or any other well known means.

The principal objects of my inventions are: to provide a simple and convenient means of throttling the air by hand, to regu ate the blow to suit the working conditions which usually require a light blow for startingand a hard blow for regular work, also to-move and hold the tool pistonat one or the other end of the cylinder as the case may require, also to simplify and cheapen the "construction as will hereafter be set forth.

To this end, my inventions consists of the following'combination and arrangement of 5 parts: A combination hand valve and directing handle by means of which the operator is able to throttle the airsupplied to one or both of the main cylinder ports without removing his hand from the directing handle: by combining with the hand valve a bypass passing through the throttle and placing in the bypass a check valve in such a manner as to allow air to move in only one direction in'said bypass: by so placing the hand valveas to allow the air to move in the desired direction through the main port: by so throttling the air as to force thepiston to make a lightor a hard stroke or to force the piston to one or the other end of the cylinder as different circumstances may require. Also in certain details hereafter described and pointed out in the claims by which the construction is simplified that the expense of manufacture and maintenance is reduced. 1

In star-ting the tool andin various other conditions of operations in handling it, a changein the force of the blow is often required to operate the machine to the best advantage. It is occasionally 'desired to push the tool piston to the forward end of the cylinder, as when placing the machine in the'desired position for working. Also 7 it may benecessary to pull the piston to the rear end of the cylinder as when preparing to strike the first blow or when the pick or drill becomes stuck in the coal or rock. To meet these conditions I employ a rotary hand-valve (hand operated valve) which,

operating in connection with the bypass and check valve, will: 1. Control the amount of air passing into and out from the cylinder through the main port. 2.v Prolong the life of the check valve by saving it from continual wear during the ordinary operation of'the tool. 3. Allow the passage of air through the bypass out of the cylinder only.

I 4. Allow the'passage of air through the by.-

pass into the cylinder only.

5.'Simplify the construction and cheapen the cost of manufacture by forming the bypass valve to slide lengthwise inside'the hand valve.

Thecoal pick has a cylinder T which is mounted .on a carriage that runs on a track within striking distance of the, working face of the coal as shown in Fig. land is connected with the oscillator by rather short tubular connections F1 and F2. (SeeFig. 1.) Pneumatic coal picks must be very I strong or they would be bent or broken by the rough usage incidental to their use.

Six hundred pounds is a common weight, and lt makes about 3 strokes or more per second. The machine runner selects a point the pickthan ifhe uses only one. And

when both hands arev on the directing handles H1 and H2 it isa rotary'movement of the handle that is easiest for him to make. This difficult with hard than with light blows, because the pick glances farther if the pick strikes the coal harder. constructed a rotary or swivel directing hand'valve H, the turning of. which throt- .tles theair supplied toithe pick and thereby makes a lighter blow, which, in turn, is easier to direct.

In'Figs. 3 to 7 are shown in detail the hand valve H with the handle H1. In a general way it consists of a hollow cylindrical glancing or jumping of the 7 pick which 1s so difficult to control is more I have, therefore, 1

stem that fits closely but loosely in a 'hole formed lengthwise inthe' cylinder casting T. As the mechanisms serving: the two main ports 37 and F6 are essentially alike, I will now describe that which serves the front end port 37 and from which" with the 7 aid of the drawing and description the other mechanism will be readily understood. Formed in the; hand valve H and V registering with the port 37 the gate G2 that allows a free passage of air from the main port 37 to the tubular connection F2 7 that serves the forward end of the cylinder when the valve H is in the ordinary working position, called the middle position and shown in Fig. 14. j The rotation of the valve H closes the air passage leading to the port I 37 as will be hereafter described. A bypass 132 is formed (preferably passing through the stem) and connects the main port 37 with the air tube F2 when the hand valve His closed as shown in Fig. 13. In-

side the hand valve H and closing theby- 7 pass B2 is the check valve 022 that opens by pressure on the end from. one direction in thebypass and is not opened by pressure from the opposite direction. in the bypass.

The check valve o2 is closed by the spring 82. The piston head itself when moving toward the end of the cylinder closes the main port and thereby forms a pocket of-air on which to cushion the piston :toprevent it striking'the cylinder head and wrecking the tool. The natural rebound of the piston so cushioned usually carries'it far enough forces open against the pressure of the spring 32. The succeeding reverse impulse of air however in the front end oft-he cylinder, does not press against. th'eend' of the check valve, so cannot open it.

Simultanously with the action in the front end of the cylinder above described. the action at the back end' of the cylihdbr is as follows: The incoming-air from the pressor or oscillator presses on. the end of the check valve 111 which it opens ("against the spring 31) and enters the rear end of the cylinder through bypass Bl (as shown by the arrow 51) in Fig. 9. The valve then closes and the inclosed air has no effect in opening the check valve 211, so it does not allow the confined air in the cylinder to escape. The full effective air pressure on the piston is thus used to force the piston forward and none of the effective air pressure to drive it backward. If the tool should get stuck when in the outward position shown in Fig. 10, the hand valve H would be given a turn to the position shown in Figs. 10 and 12. When in this position the air can enter the forward end of the cylinder through the check valve 412, (see Figs 10 and 16) but cannot leave it through the same valve. Also the air can leave the rear end through bypass B1 and check valve 011, but cannot enter through this check valve. The full effective pressure on the piston is thus used to force the piston backward but none of the effective pressure to drive it forward. It will thus be observed that the two check valves 7 p2 and t1 cooperate to produce a movement of the piston in the same direction. The end of the cylinder to which the piston is driven depends on the position in which the hand valve H is placed. This valve mechanism at each end of the cylinder just described is independent of the mechanism at the other end. In other words the valve mechanism as shown at either the forward or rear main port could be omitted and the connecting tube F1 or F2 led direct into the end of the cylinder in the ordinary way without affecting the action of the valve mechanism just described, at the other port of the cylinder. In other words suppose the pressure in each end of the tool cylinder alternates between three and five atmospheres. That is the effective pressure of two atmospheres acts alternately in each end of the cylinder; If now we allow entrance onl yotair iirth'e; front end of the tool cyl' inder shown in- Fig; 10 we raise the pressure in the front end to five atmospheres.

And as a result the high pressure in therear end of the tool cylinderis balanced, and there' is produced only pulsations of effecti ve pressure in the front end of the tool cylinder; @he to every other stroke of the compressor; But if" there is also acooperatii'rg valve 411 in the rearend of" the cylinder as shown i'nFig-i 10 it would at the same time allbw only escape of airf'rom the rear end of the cvlinder and there would be prod'ucedonly low pressure in the rear end' of the tool cylinder: This would result ina continuous pressure (as distinct from the pulsating pressure above noted) being exerted fronrthe forward end of the tool cyl'- ihder. If in Fig.-l0 the hand valve is turned so that the front end valve allows only the escape of air from the tool cylinder, then low pressure only would be produced in the forward end of the cylinder. This would result in pulsations of effective pressure in the rear end of the tool cylinder. If there was a cooperating valve in the rear end as in Fig. 9 we would have a continuous effective pressure in the rear end of the cylinder and no effective pressure in the forward end of the cylinder. The hand valve H may also be used to throttle or partly throttle the oscillating currents of air passing the main ports 37 and F6. In Fig. 17 the hand valve is shown in its left closed position, and in Fig. 18 the hand valve is in the right closed position.

In Fig. 14 the hand valve is in middle position and the main ports 37 and F6 are both open. By my invention, the bypasses B1 and B2 are closed during the ordinary working of the tool and the check valves t1 and Q22 are thus saved much useless wear. The hand valve H is kept in the various five positions above mentioned by the latch L that fits into the various notches as shown in Fig. 11; thus notch 14a is the middle position used in ordinary working and is the same as shown in Fig. 14:. Notch 17 a corre sponds to the position shown in Fig. 17 where the air is cut oil'. The notch occupied by the latch in Fig. 11 corresponds to the position shown in Figs. 9 and 15 where the piston is being forced outward. Notch 18a corresponds to the position shown in Fig. 18 where the air is also cut off. Notch 12a corresponds to the position shown in Figs. 10 and 12 where the piston is being forced backward or inward.

An ordinary manually operated faucet on the top of the pick to regulate the air to the ordinary pick is common, but the operator must use only one hand for directing the pick while he employs the other hand to operate the faucet. With my device he can tially as described.

2.7In. a pneumatic tool of the class deuse the'same hand to direct theblovvs While he regulates the supply of air to produce the force ofstroke that is needed.

Having thus described my invention, I

inder and running through said ports,

notches in said plug registering with said ports, a bypass passing through said hand valveat each of said ports and reversely act ing check valves in, said bypasses, substan-- scribed the combination With a tool cylinder having a piston therein, of front and back ports opening into the tool cylinder onopposite sides of the piston, port valves in both of the ports, a bypass through each port valve, a check valve ineach bypass formed to slide lengthwise in said port valve and adapted When in'one closed position of the port valve to be opened by pressure from Within the cylinder only,,and vvhen in the oppositeclosed position ofthe port valve to be opened by pressure froinwithout the'cylinderj only, the said port valves being re Witnesses: V r v g V HARRY T. GETTINs, VICTOR G. LYNOH Gopiesof this patent may beobtained for five cents each, by addressing the Commissioner of Bate ms,

- Washington, D, C.

action, substantially as de- CHARLES OT sf PALM R, 7 a 

